According to Wikipedia:
The known active constituent is a trans-neoclerodane diterpenoid known as Salvinorin A, chemical formula C23H28O8.[21] It is present in the dried plant at about 0.2%.[22] Unlike other known opioid-receptor ligands, salvinorin A is not an alkaloid—it does not contain a basic nitrogen atom
in otherwords: IT MAKES CATS FUCKING SCARY
(, Tue 17 Jun 2008, 13:42, Reply)